In order to hinder ingress of aggressive ions from sea water via cracks efficiently, it is of great significance to realize rapid self-healing in concrete. In this study, the feasibility to promote self-healing of cracked cement paste in sea water by using triethanolamine (TEA) was investigated. To enlarge the effects of TEA, 0.5–2% (by mass of cement) TEA was added into cement pastes and it was found that TEA can dramatically enhance the self-healing efficiency in sea water conditions. In cement pastes with TEA more than 1% (by the mass of cement), the crack closure ratio can reach 100% at a healing period of 1 d in sea water, 20 times faster than a cement paste without TEA. The permeability of cracked specimen with TEA decreased by about 90% after a healing period of 2 days. At the early stage of self-healing promoted by TEA, large amounts of Mg(OH)₂ was formed, accounting for about 70 wt% of the reaction products of self-healing. It is well known that TEA can not chelate with Mg²⁺ ions. Therefore, the large amounts of Mg(OH)₂ leading to complete self-healing of cracks in a short time indicates that the promotion on self-healing by TEA was not mainly caused by the chelating action. Experimental results show that in sea water with the high concentration of Mg²⁺, the property of TEA to increase its surrounding OH⁻ concentration induces the formation of Mg(OH)₂. This is the main mechanism of the promotion on self-healing of cracks by TEA in cement paste in sea water.

为了有效地阻止侵蚀性离子通过裂缝从海水中侵入，实现混凝土的快速自修复具有重要意义。在这项研究中，研究了使用三乙醇胺（TEA）促进海水中裂化水泥浆自愈的可行性。为了扩大TEA的效果，在水泥浆中添加了0.5–2％（按水泥质量计）的TEA，发现TEA可以显着提高海水条件下的自愈效率。在TEA含量大于1％（按水泥质量计）的水泥浆中，在海水中愈合1 d时，裂缝的闭合率可达到100％，比不含TEA的水泥浆快20倍。经过2天的修复后，TEA破裂的试样的渗透率降低了约90％。在TEA提倡的自我修复的早期阶段，形成₂，约占自愈反应产物的70重量％。众所周知，TEA不能与Mg ²⁺离子螯合。因此，大量的Mg（OH）_2会在短时间内导致裂纹完全自我修复，这表明TEA对自我修复的促进作用主要不是由螯合作用引起的。实验结果表明，在海水中有Mg的高浓度²⁺，TEA的属性，以增加其周围的OH ^-浓度诱导的Mg（OH）的形成₂。这是海水中水泥浆中TEA促进裂纹自愈的主要机理。